File formats for 3D Printing. Modeling software can save models in different types of files (formats). The file formats refer to the specifications that determine what must be written within a file and what is not, and therefore what is necessary to write and what can be read within these files. Here we will see only some useful aspects of the file formats for 3D printing.
A G-code file for example, contains only text, and can be read and / or modified simply by using the windows notepad, or vim, gedit in Linux, but it cannot be “opened” with a modeling software or, it could be possible but most likely (it is possible that the software can automatically recognize the file format and display its contents based on the capabilities of the software itself) you would still see only text or text.
NOTE: Some types of files can be saved in format binary or text. Some “formats” may be proprietary, therefore defined by the company that produced the software, and / or dependent on the type of software (CAD or manual modeling), etc.
If, for example, the work is saved in a file made with the CAD in the default format (owner for example .dwg or .dxf), the file will not only contain the data necessary to recreate the mesh alone. But also all the data necessary to visualize the dimensions, the color of the faces, the thickness of the lines etc.
In a CAD program it is possible to assign and display the dimensions, or the measurements of a hole, its depth, etc., in different colors and with different characters (fonts).
However, this data is not needed by a printer to recreate the model (or even by a software for modeling), since each face of the mesh has a well-defined position etc. Furthermore it is not possible to know how the model is saved inside the proprietary files except by reading the manuals when it is available.
Remember that a mesh is made up of a series of points (vertices) that are connected together in the right way to shape the mesh itself.
Triangle fan ( Microsoft )
Triangle strip ( Microsoft )
Usually then a mesh, saved in a .stl or .obj file will be easier to open and to modify using a software for modeling.
To exchange files between different software requires that the files can be “understood” by both software.
When you want to print a model you proceed to “export” it to a file, whose format is understandable by the program that will have to be able to read its contents, display it and, if necessary, convert it again. In the case of 3D printing, the slicer. In the new file, exported by the slicer, some data will no longer be present, but only those that will be used by the printer to reproduce the model.
For example, if you print with a single color all the information relating to the color of the mesh are not useful to the printer and can be discarded, so this information is lost, and, if you wanted to modify the file generated by the slicer with some particular software, almost certainly the mesh would have only one color.
This means once again, that the exported file (ie not saved in the original format commonly used by the software) it may no longer contain all the information needed by the CAD to recreate the design or model, and probably contain new ones.
In this situation the CAD, for example, may not be able to show the model and / or all its features (features). If the CAD, or the software you intend to use, can import the file, based on the form Ato with sui has been previously saved, then there is a good chance that something can be recovered, but most likely, something will be lost. Always save the file in the standard or default format of the software you are using. This is because it guarantees the possibility of being able to modify the model again and again if necessary and never lose any part of it, and only then export the file in the desired format. Especially in the case of a mechanical CAD model where every dimension is absolutely important.
Some file formats (generated by CAD programs and 3D modeling)
Their extension, that is the letters after the last point, indicate the format in which they were written and with which they can be read and understood.
.dwg, .dxf, .grb, .IGES, .skp, STEP
.3ds, .BLEND, .c4d, .dae, .fbx
Most common formats for 3D Printing
Stereo Lithography .stl ( Wikipedia )
Wavefront OBJ .obj ( Wikipedia )
G-Codes .gcode ( Wikipedia )
G-Code .gcode ( RepRap Wiki )
Other files ( Wikipedia )